Millionaire MP Malcolm Turnbull and billionaire businessman David Smorgon have had their credit card details published on the internet by hackers.
The loose-knit hacking movement Anonymous claimed on Sunday through Twitter that it had stolen thousands of credit card numbers and other personal information belonging to clients of US security firm Stratfor, which provides information to clients on business, economic, security and geopolitical affairs.
Hackers posted a link online to what they said was Stratfor's private client list.
They also posted images claiming to show receipts for donations made to charity using credit cards belonging to Stratfor clients, including the US Department of Defense and Department of Homeland Security, and other Australian organisations.
The Australian Department of Defence has a contract with Stratfor for a database subscription until November 2012.
The details of Turnbull, the opposition communications spokesman, and Smorgon, founder of Generation Investments, were also among those published online, The Australian reports.
A spokesman confirmed that Turnbull's private details had been published.
Anonymous claimed on Sunday that it was able to steal the credit card data because it was unencrypted.
"If Stratfor would give a s*** about their subscriber info, they wouldn't store CC/CCV numbers in cleartext, with corresponding addresses," according to one tweet.
Smorgon said that he had cancelled his credit card upon hearing the news.
"I was advised [by Stratfor via email] a few days ago on what had happened," Smorgon told The Australian.
"I was totally surprised [by the hacking] ... I have cancelled my American Express credit card and I was obviously not the first to do so.
"This is a warning bell for everyone, and I guess it's the cost of doing business online."